Steam-actuated rock-drill



2`Sheets-Sheet 1.

D. Y .0 L L W o n a. m M4 0 m l STEAM AGTUATED. ROCK DRILL. No. 481,632.

2 Sheets-Sheet 2.

Patented Aug. 30, 1892..

(No Model.)

( i de j UNITED STATES PATENT OFFICE.

SETH LLOYD AND WILLIAM R. LLOYD, OF WEST NEW BRIGHTON, NEW YORK.

STEAM-ACTUATED ROC K-DRI LL.

SPECIFICATION forming part of Letters Patent No. 481,632, dated August 30, 1892. Application filed December 9, 1890. Serial No. 374,074. (No model.)

To @ZZ whom it may concern:

Beit known that we, SETE LLOYD and WIL- LIAM R. LLOYD, of West New Brighton, in the county of Richmond and State of New York, have invented certain new and useful Improvements in Steam-Actuated Rock-Drills; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to steam -thrown valve and variable-stroke rock-drills and analogous machines that perform their work bya succession of blows. The principal parts comprising such devices are a cylinder, piston, and valve, with ports to operate them. The ports that operate the piston are controlled by the valve, and the ports that operate the Valve are controlled by the piston. With previous constructions, said valve-operating ports are so located in the cylinder that the valve will be operated when the piston is at its shortest stroke, which is generally at the middle of the cylinder, the object being to secure a variable stroke, and the effect is to throw the valve before the piston can complete its full stroke, with the following undesirable results: The first half stroke of the valve cuts oif the steam, driving the piston at a time when its increasing velocity requires most steam and also cuts off the exhaust, causing the piston to cushion on what steam remains in the cylinder. The last half movement admits steam for the return stroke and also opens the exhaust on the opposite end. In case the valve is retarded sufficiently to travel only one-half its stroke by the time the piston completes its full stroke the exhaust for the return stroke will be restricted, thereby weakening the pull-back, or recovery, and decreasing the speed of the drill. It the valve is not retarded, steam will be admitted in front of the piston before it completes its full stroke, thereby decreasing the force of the blow.

To overcome these defects is the object of our invention, which object we attain by using an auxiliary valve to time the movements of lthe main valve in such mann er that the piston will complete its full stroke before the main valve reverses to admit steam into the cylinder for its return stroke. Said auxiliary valve is adapted to be controlled by the piston, through ports so located in the cylinder that the piston will operate the auxiliary valve when at its shortest stroke, which is preferably in the middle of the cylinder, where a groove in the piston will reciprocate across annular grooves in the cylinder on any stroke, from scarcely more than a vibration to a full stroke. As it will be seen that after said groove in the piston crosses the lower one of said grooves in the cylinder the piston will require an interval of time to complete its full stroke, it is apparent that the auxiliary valve must be constructed and regulated to consume the same time in completing its stroke in order to reverse the main valve, which is adapted to move very quickly at the proper time to admit steam into the cylinder for the return stroke of the piston. To regulate the speed of the auxiliary valve in this manner, the ports e3 that connect it with the cylinder are restricted in area or cross-section; or the induction e4 that admits steam to operate it might'be restricted. Either way will accomplish the same result, and is equallyapplicable. In practice a three-inch machine, with a sixinch stroke, working at four hundred strokes a minute under seventy pounds of steampressure, will require a one-sixteenth inch port to operate a five-eighth inch auxiliary valve with a half-inch stroke at the proper speed. This auxiliary valve is preferably made with as long stroke and as narrow ports as practical, to admit of closer regulation and to throw the main valve as quickly aspossible. It is apparent that as the auxiliary valve must consume a certain time in its travel the longer the travel the quickerit will move and the more quickly it will open the main-valve-operating ports, they being made narrow for the same purpose. The statements thus far relate only to regulating the valve on the down or working stroke. On the return stroke the auxiliary valve is regulated (inthe same manner as in the downstroke) to operate the main valve in time to admit steam into the top end of the cylinder to check the piston before it strikes the top head.

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The invention consists in certain novel features of construction and combinations and arrangements of parts, as hereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure lis a. longitudinal sectional view showing the piston and cylinder and ports partlyremoved to show the auxiliary valve. Fig. 2 is a View on the line a: :1: of Fig. l. Fig. 3 is a plan view with the valve-chest removed. Fig. 4 is a view on the line w Fig. l. Fig. 5 is a sectional view on the line y y of Fig. 1.

A representsacylinder in which a piston B is located and provided with a piston-rod B',`

with the valve D, areadapted to control the 1 ingress and egress of steam to and from"` the cylinder A.

An auxiliary' valve E is located in a valve chamber or casing e6 between the m'ainvalve D and the bore of the cylinderA and at its center is elongated and reduced to receive a ring or sleeve e5, having a flange e", adapted to enter an. annular groove in the interior wall of the auxiliary valve-chest es. The auxiliary valve E is adapted to receive steam from the space z around the-valve D, and is madewith pistons it' fi i, adapted to open-and closeY the several ports, hereinafterdescribed, to control the ingress and egress of steam to and from the ends of the main valve to oparate it,` and at the ends of the auxiliary valve-chamber elastic buffers 2. 2 are preferably located.

Located on each side of the central ring e5 is a set of ports for operating the auxiliary valve. The inlet-port e4 provides an open passage from themain valve-chest ,ato the interior of the valve-casing e6 at the edge of ring e5. The exhaust-port e3 passes-from the interior of the valve-casing e at the edge of ring e5 to the outer one of the annular grooves in the cylinder.

The piston B is provided with a longitudinal slot a', and in thecylinder the grooves bb are arranged in pairs, the upper pair serving to exhaust the top side of the auxiliary valve and the bottom pair serving to exhaust the bottom side. The grooves b connect with the auxiliary valve E and the grooves b connect with the exhaust 5 through port b2. (Shown in Fig. 5.) The longitudinal groove a. serves to establish communication between one or the other pair of grooves bb when the piston B moves toward one or the other extremity of its stroke. Grooves and ports e connect the auxiliary-valve chamber with the main steamspace z and serve to supply the ends of the main valve with steam through ports e', which also serve as eduction-ports when brought into connection with port e2, which connects with the main exhaust-port 5. In this description by the front or bottom end ot' ,the device is meant the end through which the piston-.rod protrudes, and the top or back end is the opposite end of the device.

The operation of the apparatus for throwing the piston is as follows: As shown in Fig.

I, the `parts are in the positions they assume when the piston is on its forward or working stroke. When the` longitudinal groove a' crosses the bottom groove b, the lower end of the auxiliary valve E will begin to exhaust l through ports e3 and b2 and grooves b b (bottoml end) into the mai-n exhaust 5. The upf per groove b, being covered by thesolid part of the piston B, steam will accumulateon the upper side of the ring e5 through port et and force the auxiliary valve E to theuppercnd of its chamber,which `movement on the part ofthe auxiliary valve reverses the main valve by placing the bottom end in connection with the exhaust 5 through the ports e e2 and ad# initting steam to the top end through ports e e. The parts are then in position for thereturn stroke, which is the same as the one just described, except that the direction of travel of the valve is reversed.

From the construction and arrangement of parts above described itwill be seen that the auxiliary valve is designed and the ports proportioned in a manner to allow an interval of time to elapse between the opening of the auxiliary valve, exhaust-port, and the reversing of theV main valve long enoughfor the piston to complete its full stroke on the fiorward end. 0n the return stroke the auxiliary valve is regulated to permit steam to be admitted iutothe cylinder in time to check the piston and save the back-head from violent shock.

Though in describingour invention we have mentioned steam only as the motive iiuid,we do not desire to restrict ourselves thereto, nor do we desire torestrict ourselves to the specific construction of auxiliary valve described.

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It is apparent, also, that our invention is applicable to alldirect-acting engines that per` form their work by a succession of blows.

In order to give the drill a rotary as well as a longitudinal or thrusting motion, the mechanism now to be described will be employed. The end of the cylinder A is provided with a steam-tight cap A and an elastic buffer A2, held in place bya cross-bar fand bolts f. The piston B is provided with an opening orsocket, in the walls of which a series of recesses are made for the reception of a number of pawls H, adapted to enter a longitudinal spiral groove in a rod C2, which is made to lit and slide in the opening or socket in the piston and secured at its outer end to the cylinder-head. The pawls and grooves in the bar C2 are so placed in relation to each other that when the piston moves down or toward the front head of the cylinder .the side of groove C4 in the bar C2 will act on the pawl,

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' force it into its recess, and allow it to slide over the top of the bar and drop into the groove on the other side. On the upstroke, the bottom of bar C2 acts on the paWl and jams it against the opposite side of its recess, causing the piston to follow the direction of the groove. If the drill strikes in a hole or socket in the rock and will not rotate from any cause, the bar Will turn and prevent anything from breaking, the side bolts being adjusted to give the proper amount of friction.

Having fully described our invention, what We claim as new, and desire to secure byLetters Patent, is-

l. In a Variable-stroke drill or analogous machine that requires a variable stroke of piston, the combination, with a cylinder, piston, and main valve, of an auxiliary Valve constructed and adapted to be operated by the piston at its shortest stroke, substantially as set forth.

2. In a variable-stroke drill or analogous machine that requires a variable stroke of piston, the combination, with a cylinder, piston, and a main valve adapted to move quickly, of an auxiliary valve adapted to be operated by the piston at its shortest stroke and to operate the main valve after consuming in its stroke the time required for the piston to complete its full stroke, substantially as Set forth.

3. In a variable-stroke drill or analogous machine in Which a variable stroke is required, the combination, with a cylinder, piston, and a main valve, of an auxiliary valve adapted to be operated by the piston at its shortest stroke and supplied with ports connecting it with the main steam-chest and with the interior of the cylinder, one or more of said ports being restricted, substantially as set forth.

4. In a rock-drill or analogous machine, the combination, with a cylinder having an annular groove adapted to connect With the valve and another groove connecting with the exhaust, of a piston having a longitudinal groove which serves to establish communication between the grooves in the cylinder for the purpose of exhausting the valve, substantially as set forth.

5. In a rock-drill, the combination, with a cylinder having annular grooves therein, two

`piston,the combinatiomwithacylin der,piston,

and main valve constructed to move quickly, of an auxiliary valve adapted to be operated v by the piston at its shortest stroke and having its stroke lengthened to admit of close regulation, substantially as set forth.

7. In a rock-drill or analogous machine, the combination of a cylinder, piston, and main valve With an auxiliary valve, the exhaustport of said auxiliary Valve being restricted, as and for the purpose described.

8. In a rock-drill or analogous machine, the combination of a cylinder, piston, and main valve with an auxiliary valve, the inlet-port of said auxiliary `valve being restricted, as and for the purpose described.

9. In a variable-stroke rock-drill or analogous machine that requires a variable stroke of piston, the combination, With a cylinder, piston, and a main valve constructed to move very quickly, of an auxiliary valve adapted to be operated by the piston at the shortest stroke and having inlet-ports connecting it with the main valve-chest to supply it With steam, substantially as set forth.

10. In a variable-stroke drill or analogous machine requiring a variable-stroke piston, the combination, with a cylinder, piston, and a main valve constructed to move quickly, of an auxiliary valve adapted to be operated by the piston at its shortest stroke and having exhaust ports placing it in Vcommunication With the piston, substantially as set forth.

In testimony whereof We have signed this specication in the presence of two subscribing Witnesses.

SETI-I LLOYD. WM. R. LLOYD. Witnesses:

IRVING CHAPPELL, EDWARD D. HAzELToN. 

